Victron and Raspberry for solar life

Living on the seashore is magical.

We are having windy weather and storms and for couple times a year there is no electricity. So generating something on your own makes sense here. And of course its overly cool to create normal 220V power on your own.

I have a wind generator in non-rotating and non-setup mode in the attic. We have many trees here around the house which are higher than 25 meters, so finding some 50 meter mast would be out of mind:

And as we are having a military airfield ~10km in distance, then putting up this high mast would have a lot of obstacles to overcome. Plus it would attract lightning and make noise that neighbours would not like. By the way, 20 years ago I created a wind generator on my own, from loudspeaker magnets, volvo disc brakes and Lada ball bearings. I went the same way as described here. Anyway, wind generator would not work out at this location.

So I took up the sun topic. There is sun on my roof on one area from around 11 AM until 6 PM. I measured it twice and figured out I had just 4 meters of real production area. So I got 4 pieces of QCELLS Q.PEAK DUO 315W G5, which are totally cool and black and 2020 design. James Bond and Chuck Norris have them for sure. Yes, they are 10 watts weaker than the white-background panels, but they look totally awesome:


As there are trees around everywhere, I decided to wire the panels into two series pairs. If I would hook everything up in series, then if there would be any obstacle on the panels because of tree shade, I would lose basically all production. Its just the way the panels work. If I would wire everything in parallel, the voltage would be low and partial shading would not matter so much, but I would lose with energy transfer as wires would get hot because of high amps. So going with two pairs of series connected panels seemed to be a logical choise. You don't believe I have trees here? Check this out then. Maybe you even notice some panels between them :)





For the solar controller I got a Victron BlueSolar 150/45 and bought a VeDirect Bluetooth Dongle for management.



Both needed a firmware upgrade before I could access them, the bluetooth dongle even went into error. After several retries it succeeded. I tried playing with 12V and 24V, and 24V gave better results with AGM batteries. Its nice to see over bluetooth whats going on in realtime - farming some 1.2+kw free energy between the trees is awesome result afterall:



For the inverter I chose the pure sine Victron Multiplus 24/3000/70-50 inverter, which I put to the basement with the MPPT and batteries. As nobody had ever done any firmware upgrade to it, then it was pretty entertaining to get it done before it accepted non-firmware upgrade connections over MK3-USB cable. You need to download specific firmware suitable to your product and the update could be done with VEFlash utility that runs on windows only.



After the update was done, I could see and change settings on the inverter. Default password is "ZZZ" to the management. I could put a 1.0kw floor heating following a 1.5kw water heater behind the inverter and it succeeded to warm them up on a sunny day, when panels fed 1.2kw to the system (inverter harvested 75.6 amps, 45 amps came from sun). Mainly I have used the solar power for internet, smart house, TV, lighting and fridge.



All these screens are nice, but they can be seen just locally. So I learned from the Victron site that Victron is doing some developments on Raspberry Pi called Venus OS and it can send data every minute to Victron VRM website. On the forums there was a lot of chat about Rpi3+ and they said there is no support for the latest Rpi4. Just some hackers went with Rpi4. So of course I went with Rpi4 too.


For the power supply of Rpi4 I used a 7..24V > 5V DC-DC converter with USB output, power comes directly from 24V batteries:

Connection to inverter was okay as it was over USB, but MPPT used bluetooth and this did not work out. Rpi4 has onboard Bluetooth ver 5, but the device was not shown even by "rfkill list" on terminal.   I even tried the bluetooth USB dongle - on terminal I saw the bluetooth device, it even connected to MPPT and pairing succeeded, but the solar charger was not shown on main screen. So I bought Ve.Direct to USB cable and connectivity problems were solved:





At first I missed the perfect overview I got from MPPT over bluetooth, but the Rpi4 has the same information inside like daily history etc:



The VRM portal is totally perfect and it gets information from my Rpi4 every minute:



In one month of usage during april I have gained ~100kw from the sun. One day maximum is around 7kw.

I have seen people putting tablets on the walls, which show the Raspberry screen, but I mainly view the screen on my phone or laptop, so no actual need for that. I put a tablet on the wall, but it was rarely used. So I just put some voltmeters above solar powered lamps, showing battery voltage and solar panel voltage and I am even more happy with it:


And the pig-dog-bullterrier is also happy with the 12V LED solar lights.




In the center below there is my house. The panels are facing south. Its the view the panels have every day.




In conclusion, like Mika Häkkinen would say would say in the beginning of the long press conference - shading is bad, but solar is good. Press conference is over.

Here is flight from solar panels to the seashore in the end on March: